Conventionally, a printing apparatus such as a printer or a multi-functional peripheral (MFP) capable of performing double-sided printing by handling a sheet automatically has been distributed. Such a printing apparatus needs a mechanism which reverses a sheet mechanically or the like, but is useful because double-sided printing is able to be performed without manually setting a sheet again after single-sided printing.
On the other hand, a printing apparatus which does not need such a mechanism and performs double-sided printing by manually supplying a sheet again is also proposed (for example, see Japanese Laid-Open Patent Publication No. 2006-127198). In a printing apparatus described in Japanese Laid-Open Patent Publication No. 2006-127198, an image of an even-numbered page which corresponds to a back face side at the time of double-sided printing is firstly subjected to single-sided printing in inverse order from an end page, a sheet which is discharged to a paper discharge tray after single-sided printing is completed is supplied to a paper feed tray manually, and an image of an odd-numbered page is caused to be printed on the other side (back side) which is a non-printed side of the fed sheet.
As described above, in a technology described in Japanese Laid-Open Patent Publication No. 2006-127198, assuming in advance that double-sided printing is performed, single-sided printing is performed, and thereafter the sheet having one side printed is put in the paper feed tray and a page corresponding to a back side (non-printed side) of the sheet is printed.
However, in the printing apparatus capable of performing double-sided printing by handling a sheet automatically, when performing double-sided printing, single-sided printing may be performed by an erroneous operation, and, in such a case, a mechanism which enables recovery easily is not provided, so that all sheets having one side printed are wasted.